The usual way to apply flavoring to a french fry is for the consumer to dip it into flavoring, usually ketchup. Some consumers dip their french fries into salad dressings, taco sauces and the like. This is messy. Also, use of such dips adds cost to the restaurant in which the french fries are served.
There are currently in the marketplace french fries bearing a batter coat containing flavoring. However, such coatings are flour based or gum-starch based and have a high fat content. Also, because the coating tends to be thick, it is visible and, therefore, looks different than a french fry. Finally, the flavoring is only on the outside.